This report describes an outbreak of acute pulmonary sarcocystosis
in different species of captive psittacine birds and in a Luzon
bleeding-heart pigeon (Gallicolumba luzonica) in a zoologic collection
in Brazil. A majority of the birds were found dead and had exhibited no
previous clinical signs. On gross examination, pulmonary congestion and
edema were the most common findings. Enlarged and congested livers and
spleens were also frequently observed. On microscopic examination, there
was edema, fibrin exudation, congestion, and perivascular and
interstitial lymphoplasmacytic infiltration associated with numerous
sinuous schizonts of Sarcocystis species in the lungs. Mild-to-moderate
myocarditis, hepatitis, splenitis, and interstitial nephritis were also
observed in the birds. Immunohistochemistry confirmed Sarcocystis
species in the capillaries of lungs, hearts, livers, and spleens of most
of the birds, but also in the pancreas, kidney, intestine,
proventriculus, and brain of a few birds. The probable source of
Sarcocystis species in these birds was the wild opossum (Didelphis
albiventris), a common inhabitant of a local forest that surrounds the
Belo Horizonte Zoo (Fundacao Zoo-Botanica). This is the first
documentation of Sarcocystis infection in psittacine birds and a pigeon
from Brazil.